Apparatus and Methods for Alternative Coatings Applicable to Metal

ABSTRACT

Apparatus and methods for alternative coatings applicable to metal are disclosed. According to one embodiment, an apparatus comprises a composition having, an ethylene acrylic acid copolymer; a neutralizing base; and water. The ethylene acrylic acid copolymer is about 15 percent to about 45 percent by weight concentration of the water. The apparatus further comprises metal coated with the composition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/266,893, filed Sep. 15, 2016, which claims the benefit of U.S.Provisional Patent Application No. 62/218,870, filed Sep. 15, 2015, theentire contents of each of which are incorporated by reference herein.

BACKGROUND

Many industries, including the construction industry (e.g., roof andwall manufacturers), the transportation industry (e.g., automotive andtractor trailer manufacturers) and the packaging industry (e.g., winescrew-cap closure and soda can manufacturers) use pre-printed metals,such as stainless steel, tin, aluminum and plastics in the fabricationof their end products.

Traditional solvent-based coatings and inks have flexibility, goodelongation properties and mar resistance which are useful features formetal raw materials requiring bending, folding, and/or elongating aftercoating. The solvents used in these coatings traditionally have highvolatile organic compound (VOC) concentrations. These solvents are usedto adjust the coating's rheological properties, such as viscosity,allowing for a coated product free from defects. The high VOC solventsalso minimize the effect of residual grease or dirt on the pre-coatedmetal's surface by dissolving or dispersing the contaminant. Thisresults in enhanced wetting of the metal's surface for coatinghomogeneity and good adhesion. Further, the solvents help with thecoating levelling, consistency, flow, solids setting rates, and dryingtimes.

Traditional high VOC coatings are cured or dried by solvent evaporationthrough heat and air convection. These solvent-based coatings solidifyas the solvents are driven off the liquid layer applied to thesubstrate. During the coating solidification process, organic solventsare released into the process air resulting in VOC's in the processexhaust air stream. VOCs are limited or restricted in many geographicareas by local, state and federal regulations. VOCs may include a singlecompound or a mixture of volatile ethers, acetates, aromatics, glycolethers, and aliphatic hydrocarbons. A manufacturer is typically requiredto use VOC controlling systems, such as rotor concentrators,regenerative catalytic oxidizers (RCO) and regenerative thermaloxidizers (RTO). These VOC controlling systems require high initialcapital expenses and result in ongoing operating costs. Additionally,continual costs are incurred to maintain regulatory compliance includingthe regular analytical testing of treated air streams exiting the VOCcontrolling systems, administrative costs due to inspections, reportingcosts, and fines imposed due to compliance issues.

Since a manufacturer is subjected to regulations encouraging thereduction or elimination of VOC emissions, low and zero VOC coatingshave been developed as a replacement for solvent-based coatings. Thesereplacement coatings have been introduced in various forms, includinghigh solids, waterborne, solvent-free liquid energy cured (ultraviolet(UV) and electron beam (EB)), and 100% solids for hot-melt and powdercoating applications. These alternative coatings are commerciallyavailable and successfully used for metal products that do not requireextreme deformation. However, when these readily available alternativecoatings have been applied to metal prior to extreme deformation, theyhave been shown to typically lose adhesion to the metal and/or tothemselves (inter-coating adhesion failure) resulting in the coatingflaking off of the part. These coatings have also been shown to lack therequired elasticity resulting in coating fractures as the part iselongated, such as in a deep draw process.

Further, many traditional coatings contain 4,4′-(propane-2,2-diyl)diphenol (BPA) which is now under scrutiny when used in products thatare in direct or indirect contact with foods and beverages. BPA is acommon component in metal can coatings, which are applied to protect thefood from directly contacting the can's metal surfaces.

Clearly, when foods or beverages are in direct contact with anypackaging material, measurable amounts of the packaging material'scomponents may migrate into food and can be consumed. The likelihood ofthis migration is evaluated by the FDA as a part of premarket reviewsfor food packaging materials. This evaluation is a component of theFDA's food contact notification program that assesses if the migrationlevels are safe.

Since BPA is common in many food packaging materials, heightenedinterest in the safe use of BPA for these applications has resulted inincreased public awareness as well as scientific interest. As a result,many scientific studies have appeared in the public literature. Some ofthese studies have raised questions about the safety of ingesting thelow levels of BPA that can migrate into food from food contactmaterials, such as coatings.

Although, the scientific data regarding BPA health effects is notconclusive, concerns regarding hormone disruption, cancer, and possiblyheart problems have been raised. In fact, the United States FDA amendedits food additive regulations abandoning the allowance for usingBPA-based materials in baby bottles, Sippy cups, and infant formulapackaging. Further considerations and regulatory actions are expected,so the elimination of BPA from packaging materials is prudent.

SUMMARY

Apparatus and methods for alternative coatings applicable to metal aredisclosed. According to one embodiment, an apparatus comprises acomposition having, an ethylene acrylic acid copolymer; a neutralizingbase; and water. The ethylene acrylic acid copolymer is about 15 percentto about 45 percent by weight concentration of the water. The apparatusfurther comprises metal coated with the composition.

Other features and advantages will become apparent from the followingdetailed description, taken in conjunction with the accompanyingdrawings, which illustrate by way of example, the features of thevarious embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates exemplary aluminum wine closures;

FIG. 2 illustrates an exemplary system for applying a coating to coiledmetal, according to one embodiment;

FIG. 3 illustrates an exemplary system for applying a coating to a metalsheet, according to one embodiment;

FIG. 4A illustrates an exemplary system for applying inks to a metalsheet, according to one embodiment;

FIG. 4B illustrates another exemplary system for applying inks to ametal sheet, according to one embodiment;

FIG. 5 illustrates a chart comparing a commercial oven curve for an EAAcopolymer based waterborne coating versus a traditional solvent basedcoating, according to one embodiment;

FIG. 6 illustrates a Sutherland Rub test ranking scale from 1—best, to4—worst, according to one embodiment;

FIG. 7 illustrates a Taber Adhesion test ranking scale from 1—best to6—worst, according to one embodiment;

FIG. 8 illustrates a Top-of-Shell Rub test ranking scale from 1—best to6—worst, according to one embodiment;

FIG. 9 illustrates a 70% Isopropyl Alcohol Rub test ranking scale from1—best to 7—worst, according to one embodiment; and

FIG. 10 illustrates a curing oven curve for a waterborne coating appliedusing a commercial direct roll coating process, according to oneembodiment.

DETAILED DESCRIPTION

The present disclosure describes environmentally friendly flat metalcoatings and inks together with coating and ink application processesfor metal parts including those requiring severe deformations such asacute bends and extensive stretching (e.g., deep draw metal parts) afterthe coatings and inks have been applied.

The present system and method includes applying a functional orfunctional and decorative coating, or coating/ink combination to metal(e.g., a metal sheet, a metal coil) for deep drawing applications usingcoating and ink material that contain little to no volatile organiccompounds (VOC's). According to one embodiment, the present system andmethod includes applying a coating, or coating/ink combination to bothsides of aluminum sheet metal used for the manufacture of a deep-drawscrew-caps for beverage packaging applications. However, the coatings orcoating and ink combinations can be applied to any type of metal.

Briefly, and in general terms, various embodiments are directed to acoating composition including an ethylene acrylic acid copolymer, aneutralizing base, and water. In one embodiment, the ethylene acrylicacid copolymer is about 15 percent to about 45 percent by weight of thetotal composition. In another embodiment, the ethylene acrylic acidcopolymer may include an acrylic acid content of approximately 20.5percent. 25 to about 100 molar percent of the acrylic acid functionalgroups may be neutralized with ammonium hydroxide. It has been shownthat other bases can be used to neutralize the acrylic acid functionalgroups as well, such as potassium hydroxide or sodium hydroxide. Thecomposition may have many applications, but in one embodiment, thecomposition is used as a primary coating to create tie-layer coatings,color coatings, over-varnish coatings, or as interior lacquer coatingsfor screw cap manufacturing.

In certain embodiments, about 25 molar percent of the acrylic acidfunctional groups are reacted with ammonium hydroxide. However, in otherembodiments, 100 molar percent of the acrylic acid functional groups arereacted with ammonium hydroxide. In another embodiment, ammoniumhydroxide and sodium hydroxide can be used in any combination toneutralize about 25 to about 100 molar percent of the acrylic acidfunctional groups. Further, about 25 to about 70 molar percent ofacrylic acid functional groups may be reacted with ammonium hydroxideand sodium hydroxide. In a preferred embodiment, the ammonium hydroxideneutralizes about 30 molar percent of the acrylic acid functional groupsand the sodium hydroxide neutralizes about 40 molar percent of theacrylic acid functional groups. In another embodiment, the ammoniumhydroxide neutralizes about 0 to about 100 percent of the about 25 toabout 70 molar percent of the acrylic acid functional groupsneutralized. If 0 percent ammonium hydroxide is used to neutralize theacrylic acid, the 25 to 70 molar percent acrylic acid functional groupsare neutralized using sodium hydroxide alone. If 100 percent ammoniumhydroxide is used to neutralize the acrylic acid functional groups, nosodium hydroxide is used.

In yet another embodiment, the composition may include an ethyleneacrylic acid copolymer dispersion that is about 15 percent by weightconcentration in water. The ethylene acrylic acid copolymer dispersionmay also be about 45 percent by weight concentration in water. In oneembodiment, the ethylene acrylic acid copolymer may be PRIMACOR 5980I.Further, about 35 percent to about 45 percent of the PRIMACOR 5980I'sacrylic acid functional groups may be neutralized using sodium hydroxideor potassium hydroxide.

In one embodiment, the composition may include a pigment having aconcentration between 1 and 70 weight percent pigment to ethyleneacrylic acid copolymer.

In another embodiment, the composition may include a wax having aconcentration between 1 and 50 weight percent wax to ethylene acrylicacid copolymer. The wax may be carnauba wax, and the carnauba wax may beabout 10 percent by weight concentration of the total coating solids.

Another embodiment disclosed herein is a method of forming acomposition. The method includes mixing an ethylene acrylic acidcopolymer with water at a 15 percent to 45 percent by weightconcentration, and heating the ethylene acrylic acid copolymer/watermixture with a base to neutralize 25 to 100 molar percent of the acrylicacid functional groups. In one embodiment the mixture is heated to 110°C.

The method may also including mixing a pigment with the ethylene acrylicacid copolymer dispersion at a concentration of 1 to 70 weight percentpigment to ethylene acrylic acid copolymer. In another embodiment, themethod may include mixing a wax with the ethylene acrylic acid copolymerdispersion at a concentration of 1 to 50 weight percent wax to ethyleneacrylic acid copolymer.

In one embodiment, the ethylene acrylic acid copolymer includes anacrylic acid content of approximately 20.5 weight percent. Furthermore,the method for creating the dispersion includes neutralizing 25 to 100molar percent of acrylic acid functional groups with any combination ofammonium hydroxide and sodium hydroxide. In a preferred embodiment, theammonium hydroxide neutralizes about 30 molar percent of the acrylicacid functional groups and the sodium hydroxide neutralizes about 40molar percent of the acrylic acid functional groups.

Yet another embodiment disclosed herein is directed to a method forcoating a metal substrate. In one embodiment, the method includescoating the metal substrate with a first coating composition, whereinthe first coating composition includes an ethylene acrylic acidcopolymer dispersion in water at a 15 percent to 45 percent by weightconcentration created by neutralizing 25 to 100 molar percent of theacrylic acid functional groups. The method also includes curing thefirst coating composition on the metal substrate by heating the metalsubstrate from ambient temperature, approximately 75° F., to 100° F. in5 seconds. In yet another embodiment, the first coating composition onthe metal substrate is cured by heating the metal substrate from ambienttemperature, approximately 75° F., to 250° F. in 120 seconds. Othertemperatures and times may be used for the curing process.

In one embodiment, the method may include coating the metal substratewith a second coating composition. The second coating composition mayinclude an ethylene acrylic acid copolymer dispersion in water at a 15percent to 45 percent by weight concentration created by neutralizing 25to 100 molar percent of the acrylic acid functional groups and a pigmenthaving a concentration between 1 and 70 weight percent pigment to theethylene acrylic acid copolymer.

In another embodiment, the method may include coating the metalsubstrate with a third coating composition. The third coatingcomposition may include an ethylene acrylic acid copolymer dispersion inwater at a 15 percent to 45 percent by weight concentration created byneutralizing 25 to 100 molar percent of the acrylic acid functionalgroups, and a wax having a concentration between 1 and 50 weight percentwax to ethylene acrylic acid copolymer.

Another embodiment of the method includes coating the metal substratewith coating compositions that contain no volatile organic compounds(VOC's).

Another embodiment of the method includes coating the metal substratewith coating compositions that have BPA non-intent (NI) status.

To address the shortcomings of prior solutions, the present embodimentsdescribe alternative coatings and coating/ink combinations, along withmethods of applying the alternative coating and coating/ink combinationsto metal (e.g., a metal sheet, and a metal coil) using environmentallyfriendly solvents (zero or very low VOC) or solvent free (zero VOC)coatings and coating/ink combinations, while maintaining the metal'sability to bend, fold and stretch without damage to the coating orcoating/ink on the metal's surface.

FIG. 1 illustrates an exemplary aluminum wine closure 18, according toone embodiment. Individual aluminum wine closures of this type may havedimensions of 30 millimeter diameter by 60 millimeter long and may beformed using a deep draw process on flat metal sheets precoated with asolvent based coating on both sides of the metal.

A coating is applied to a metal substrate using a coil or a flat sheetcoater. FIG. 2 illustrates an exemplary system for applying a coating tocoiled metal. The metal substrate 20 is staged in coil form at the feedto the coil coater process 24. The metal substrate 20 is unwound at anuncoiler 26 and passed to an entrance accumulator 28 to ensureconsistent feed into the coating process train. The uncoiled metalsubstrate 20 is then passed to a pre-treatment station 30, where themetal's surface is cleaned, possibly treated to increase its surfaceenergy, and possibly coated with a tie-coating, such as a size or basecoat. If the metal was coated with a tie-coating, it is then dried at adrying station 32 before being sent to the coil coater 24. The coilcoater 24 includes a prime coater station 34 that applies the main coloror functional coating to the metal substrate. The color or functionalcoating on the metal substrate is then cured in a curing oven 36. Next,at a top coat station 38 of the coil coater 24, a top coat such as aprotective over-varnish is applied to the metal substrate, and is curedin a finish oven 40. The substrate then might enter a water quenchstation 42 to quickly cool the coated metal, before entering an exitaccumulator 44 that allows for continually re-coiling the coated metalat the proper tension and rewind speed.

The coating processes may apply multiple coating layers onto one or bothsides of the metal substrate in one or multiple passes. FIG. 3illustrates an exemplary system for applying a coating to a metal sheet,according to one embodiment. As shown in FIG. 3 , metal sheets 50 may bestored in a sheet or plate feeder 52. From the sheet feeder 52, eachmetal sheet 50 is fed to a conveyor (not shown). The sheets may betreated to clean and increase their surface energy (not shown) prior tocoating application at the application roller 54. During the coatingapplication, the sheet is supported underneath by a pressure roller 56.As shown in FIG. 3 , the conveyor transfers the metal sheet to a basecoater 58 operation, where the metal sheet 50 is fed between theapplication roller 54 and the pressure roller 56. A coating tray 60transfers coating material to the application roller 54 using a seriesof rollers 62, and the application roller applies the coating to eachmetal sheet as it passes. After the coating material is applied at thebase coater 58, the metal sheet 50 is sent into a wicket oven 64 thatincludes wickets 66 that hold and convey individual metal sheets throughthe oven at a specified rate. The coated metal sheets are heated, dried,and cooled in the wicket oven 64 at specified temperatures and are thentransferred to a sheet or plate stacker 68.

A coating is a liquid that may contain, but is not limited to, binders,pigments, dyes, or waxes applied to the interior and/or exterior of asubstrate (e.g., aluminum metal) for decorative, functional, ordecorative and functional purposes. The coating may be applied usingtechniques to completely cover the substrate, or it may be applied tospecifically cover selective parts of the substrate. These includetie-layer coatings, including clear and base—relatively low pigmentcontaining—coatings, applied to assist adhesion of subsequent coatingsto the metal, color coatings for decorative purposes and over-varnishcoatings to protect the color coats and printed artwork.

Coatings that are applied to the interior and exterior surfaces of ametal packaging component may have different functions depending on theapplication of the component. For example, an interior coating on ametal packaging component directly contacting the food product protectsthe metal from corrosion by the food contents and protects the food frommetal contamination. Interior coatings may also contain agents to aid inthe functionality of the finished products. For example, slip agents,such as waxes, may be used in the case of screw cap closures to reducethe torque required to remove the cap from a bottle. Exterior coatingsare applied for decoration, to protect the package or packagingcomponent against corrosion, and to protect the printed design frommarring or abrasion.

Ink is applied to a flat metal sheet either in direct contact with themetal or over a coating previously applied to the metal using asheet-fed offset lithography printer. FIGS. 4A and 4B illustrateexemplary systems for applying inks to a metal sheet. In one embodiment,offset printing consists of an inked image being transferred from aplate to a blanket and then transferred to the metal's printing surface.These systems may be used with a lithographic process, employing ahydrophobic ink, including ultraviolet curable inks, and water-basedfountain solution applied to an image carrier. The ink is applied to theimage carrier via rollers along with a fountain solution. Thenon-printing area of the image carrier attracts the fountain solutionthat repels the ink keeping the non-printing areas ink-free. Inks may beapplied to the surface of cured coatings to add solid color ordecorative elements to the metal. These inks can then be cured andprotected by over-coating with a clear over-varnish coating.

As shown in FIG. 4A, metal sheets 70 may be stored in a sheet or platefeeder 72. From the sheet feeder 72, each metal sheet 70 is fed to aconveyor (not shown) and then to a lithograph coater 73. There may be ablanket cylinder 74 on one side of the conveyor and a pressure roller 76on the opposite side of the conveyor at the lithograph coater 73. Inkapplicators 77 transfer ink through a series of rollers to the blanketcylinder 74. As shown in FIG. 4 , the conveyor transfers the metal sheetto the lithograph coater 73, where the metal sheet 70 moves between theblanket cylinder 74 and the pressure roller 76, and the blanket cylinder74 applies the coating to each metal sheet as it passes by on theconveyor. After receiving the inked image at the lithograph coater 73,the metal sheet 50 may be sent to an over-varnish coater 78 thatincludes an application roller 80 and a pressure roller 82 on oppositesides of the conveyor. A varnish tray 84 storing over-varnish is appliedto the application roller 80 through a series of rollers 86, and theover-varnish is then applied to the metal sheets by way of theapplication roller 80. After receiving varnish, the coated metal sheetsare then sent to a wicket oven 88 that includes wickets 90 that thathold individual metal sheets. The coated metal sheets are dried in thewicket oven 88 and then transferred to a sheet or plate stacker 92.

As shown in the embodiment of FIG. 4B, metal sheets 100 are fed into anoffset printing assembly between an impression cylinder 102 on one sideand an offset cylinder 104 on the opposite side of the metal sheet 100.Additional rollers 106 may also be used to help feed the metal sheetthrough the printing assembly. Ink applicators 108 transfer ink througha series of rollers to a plate cylinder 110 as shown in FIG. 4B. A watertray 112 storing water (or composition including water) is applied tothe plate cylinder 110 through a series of rollers 114. From the platecylinder 110, the ink is transferred to the offset cylinder 104. Whenthe metal sheet 100 is between the impression cylinder 102 and theoffset cylinder 104, the offset cylinder 104 applies the ink coating tothe metal sheet 100 as it passes through the offset printing assembly.As with the above embodiment described in FIG. 4A, the metal sheetincluding the inked image may be sent to an over-varnish coater, and maythen be sent to an oven for curing.

The present system provides one or more desirable properties for thecoating and coating/ink combinations including, but not limited to,decreased curing energy, decreased curing time, strong adhesion tometal, good solvent rub resistance, good abrasion resistance, extremeflexibility, ability to elongate more than 250%, acceptable blockingresistance in real-world environments, and BPA non-intent (NI) status.The present system may include a pre-coating metal treatment process toremove hydrophobic contaminants and to increase the surface energy,featuring, but not limited to, direct flame, ozone, corona, and/orplasma. The present system may also include a coating applicationprocess, featuring, but not limited to, roll, reverse roll, gravure, dryoffset, wet offset, slot die, curtain, knife, rod, pressure rod andspray coater technologies. The system may further include apost-application curing process for the coating, including, but notlimited to, the removal of environmentally friendly solvents, such aswater using forced convection, forced convection heated air, inductionheating, induction heating combined with forced air, IR energy, IRenergy combined with forced air, radio frequency and radio frequencycombined with forced air. Further, the present system may include a UVink printing process to apply decoration to the cured waterbornecoatings. The ink printing process includes but is not limited to,offset lithography, flexo, inkjet, xerography, and gravure. The processto cure the ink includes but is not limited to UV light generated frommercury vapor lamps, iron doped mercury vapor lamps, gallium dopedmercury vapor lamps, fluorescent lamps, and LEDs.

Using this technology results in environmentally friendly coatings andinks requiring lower energy and time to cure than traditional high VOCsolvent coatings and inks. An example for this improved curingefficiency for coating application can be seen in FIG. 5 comparing thecommercial oven curves for the technology disclosed herein (waterbornecoating) and the traditional solvent based coating system.

The metals coated and decorated using the technologies described hereinwill function well on flat sheets and have excellent performanceproperties for challenging deep draw applications. Further, regardingfood safety, the cured coatings can be designed to have BPI-NI status.

In accordance with one embodiment, a primary waterborne coatingcomposition is provided comprising ethylene acrylic acid (EAA)copolymer, a neutralizing base, and deionized or softened water. A solidEAA copolymer in pellet form is agitated in heated water containing abase. The base, which can include a combination of compounds, is addedat a prescribed concentration to react with a desired percent of the EAAcopolymer's carboxylic acid groups. Various relative amounts of EAA,base(s) and water are used in conjunction with agitation and dispersingtemperatures to change the resulting waterborne coating characteristics,including the EAA particle size and coating viscosity. For example, bychanging the acrylic acid neutralization from 30 to 70 molar percent,and EAA copolymer concentration in water from 20 to 43 percent by weight(agitation intensity and dispersing temperatures were held constant)stable EAA dispersions having average particle sizes of 15 to 450 nm andviscosities of 75 to 3000000 cP were made. The resulting waterbornedispersion can then be tuned to perform optimally in various coatingapplication processes.

The resulting EAA coating adheres strongly to aluminum but it also has atendency to strongly adhere to itself. This property of EAA coatings iswell known and is the reason that one of its primary uses in industry isas a heat-seal coating. In a sheet metal coating application, whereadhesion of individual sheets to one another is not desired, thisproperty can lead to a defect known as “blocking”. Blocking occurs whenneighboring aluminum sheets in a stack adhere to one another.Effectively, the sheets become bonded to each other resulting incommercial processing difficulties or the need for the raw materialbeing discarded as waste. The disclosed process addresses this issuewith a straightforward modification to the coatings in the layerscontacting each other within the stack of flat sheets along withpotential coating manufacturing, and coating application processcondition changes.

Depending on the finished part's requirements, the EAA coated flat sheetmetal can be coated with a single coating containing pigments or otheradditives, such as waxes, in order to change the appearance orperformance properties.

Although the EAA coating can be used as a single coat, this technologyis amenable to multi-coat systems. Depending on the metal or thedecorative color requirements, a tie-layer consisting of a clearsize-coating or “lightly” pigmented base coat might be necessary. If acolor coating is required and does not adhere to the metalsatisfactorily, a clear size-coating comprised of the primary EAAdispersion can be applied and film-formed to the metal first. Thiscoating is designed to adhere strongly to aluminum and to a secondcoating comprised of the primary EAA dispersion mixed with any number ofcompatible pigments, e.g. a color coating. Further, if the color coatingrequires protection, or has a tendency to cause blocking defects, athird coating can be applied comprised of the primary EAA coating mixedwith a compatible wax dispersion. Finally, the food contact side of themetal may be coated with a BPA-NI EAA coating mixed with food contactapproved pigments and/or waxes to improve processing efficiencies orperformance on the integrated package.

Another aspect includes the use of free radical or cationic UV inks toprint over the EAA coating applied to the flat metal. Althoughfree-radical UV coatings are not commonly known to have elongationproperties required for use in deep draw processes, the inventors havediscovered that they may be used successfully if the oligomer/monomersystem is designed to strongly adhere to the EAA coating prior to, andduring, the metal elongation process. In essence, properly formulated UVinks “ride” the high elongation EAA coating, allowing them to functionin deep draw applications. Using this approach, a size coating, basecoating, or primary color coating might be overprinted with 100 percentsolids UV inks, as a flood- or spot-print, to add overall color coverageor selective artwork to the metal prior to deep drawing. This technologycan include the printing of specialty artwork designed to reveal theimage after the metal is distorted (distortion printing), such as in adeep draw application.

According to one embodiment, commercially available waterborne coatingssuch as Michelman 4983R (Ethylene acrylic acid copolymer dispersion),Michelman P1853 (Ethylene acrylic acid copolymer dispersion), Michelman4983RHS (High solids, larger particle size version of Michelman 4983R),Michelman MDU20 (Proprietary polymer dispersion), Dow Adcote 37P295(Ethylene vinyl acetate copolymer dispersion), Dow Adcote 37-220(Ionomer of ethylene copolymer dispersion), BASF Joncryl 60 (Ammoniatedsolution of styrene acrylic resin), BASF Joncryl 74A (Acrylic copolymeremulsion), BASF Joncryl 77 (Acrylic copolymer emulsion), BASF Joncryl 89(Acrylic copolymer emulsion), BASF Joncryl 1695 (Acrylic copolymeremulsion), DOW HYPOD™ 8503 (High molecular weight polyolefindispersion), DOW HYPOD™ 1001 (High molecular weight polyolefindispersion), and DOW HYPOD™ 9105 (High molecular weight polyolefindispersion) may be used alone or in combination as a coating forapplication to flat sheet or coil metal.

According to one embodiment, a waterborne coating is made using anethylene acrylic acid copolymer having an acrylic acid content ofapproximately 20.5 weight percent. Solid EAA pellets are mixed indeionized water between approximately 15 and 45 percent by weightconcentration with ammonium hydroxide to neutralize 25 to 100 molarpercent of the acrylic acid functional groups. The mixture is heated toapproximately 110 C (although it may be heated between about 85 C and140 C) under agitation. The resulting EAA dispersion is used as aprimary coating for application to flat sheet or coil metal.

In one embodiment the waterborne coating is made using an ethyleneacrylic acid copolymer having an acrylic acid content in a range from19.5 to 21.5 weight percent. In this embodiment, solid EAA pellets aremixed in deionized water at a 45 percent by weight concentration withammonium hydroxide to neutralize 25 molar percent of the acrylic acidfunctional groups. The mixture is heated to 110 C under agitation. Theresulting EAA dispersion is used as a primary coating for application toflat or coil metal.

In another embodiment, a waterborne coating is made using an ethyleneacrylic acid copolymer having an acrylic acid content in a range ofapproximately 20.5 weight percent. Solid EAA pellets are mixed indeionized water at a 15 percent by weight concentration, heated to 110C, and under agitation 100 molar percent of the acrylic acid functionalgroups are neutralized using ammonium hydroxide. The resulting EAAdispersion is used as a primary coating for application to flat sheet orcoil metal.

According to another embodiment, waterborne base and color coatings aremade by mixing appropriate pigments, at concentrations ranging from 1 to70 weight percent pigment to EAA copolymer solids, into EAA dispersionscreated using EAA pellets having approximately 19.5 to 21.5 weightpercent acrylic acid mixed with deionized water at 20 to 43 weightpercent EAA in water and having the acrylic acid functional groupsneutralized from 30 to 70 molar percent using ammonium hydroxide. Theresulting EAA dispersions are used as base or color coatings forapplication to flat sheet or coil metal.

According to another embodiment, waterborne protective over-varnishcoatings are made by mixing compatible waxes, at concentrations rangingfrom 1 to 50 weight percent wax to total EAA copolymer solids, into EAAwaterborne dispersions created using EAA pellets having from 19.5 to21.5 weight percent acrylic acid mixed with deionized water at 20 to 43weight percent EAA in water and having the acrylic acid functionalgroups neutralized from 30 to 70 molar percent using ammonium hydroxide.The resulting EAA dispersions are used as protective over-varnishcoatings that also minimize the potential for blocking in coated flatmetal sheets or coils.

According to another embodiment, a waterborne coating is made using anethylene acrylic acid copolymer having an acrylic acid content from 19.5to 21.5 weight percent. Solid EAA pellets are mixed in deionized waterat 25 percent by weight EAA with ammonium hydroxide and sodium hydroxideto neutralize 70 molar percent of the acrylic acid functional groupswhere the sodium hydroxide is used to neutralize 40 molar percent of theacrylic acid functional groups and the ammonium hydroxide is used toneutralize the remaining 30 molar percent. The mixture is heated to 110C under agitation. The resulting sodium ionomer EAA dispersion is usedas a primary coating for application to flat metal or coil.

According to another embodiment, waterborne base and color coatings aremade by mixing appropriate pigments, at concentrations ranging from 1 to70 weight percent pigment to total EAA copolymer solids, into EAAwaterborne dispersions created using EAA pellets having approximately20.5 percent by weight acrylic acid mixed with deionized water at 25 to40 weight percent EAA and having the acrylic acid functional groupsneutralized from 30 to 70 molar percent using ammonium hydroxide andsodium hydroxide. The sodium hydroxide is used to neutralize from 0 to100 percent of the overall 30 to 70 molar percent neutralized. Theresulting EAA sodium ionomer dispersions are used as base or colorcoatings for application to flat or coil metals.

According to another embodiment, waterborne protective over-varnishcoatings are made by mixing compatible waxes, at concentrations rangingfrom 1 to 50 weight percent wax to total coating solids, into EAAwaterborne dispersions created using EAA pellets having from 19.5 to21.5 weight percent acrylic acid mixed with deionized water at 25 to 40weight percent EAA and having the acrylic acid functional groupsneutralized from 30 to 70 molar percent using ammonium hydroxide andsodium hydroxide. The sodium hydroxide is used to neutralize from 0 to100 percent of the overall 30 to 70 molar percent neutralized. Theresulting EAA sodium ionomer dispersions are used as protectiveover-varnish coatings that also minimize the potential for blocking incoated flat metal sheets or coils.

According to a preferred embodiment, waterborne protective over-varnishcoatings are made by mixing compatible waxes, at concentrations rangingfrom 1 to 50 weight percent wax solids to total EAA copolymer solids,into EAA waterborne dispersions created using EAA pellets having from19.5 to 21.5 percent by weight acrylic acid mixed with deionized waterat 20 to 30 weight percent EAA and having the acrylic acid functionalgroups neutralized from 65 to 75 molar percent using ammonium hydroxideand sodium hydroxide. The sodium hydroxide is used to neutralize from 50to 70 percent of the overall 65 to 75 molar percent neutralized. Theresulting EAA sodium ionomer dispersions are used as protectiveover-varnish coatings that minimize the potential for blocking in coatedflat metal sheets or coils.

According to certain embodiments, the wax used in the protectiveover-varnish may be carnauba or oxidized high density polyethylene. Inother embodiments, the wax used in the over-varnish may be a fatty amideor bisamide, montan ester, microcrystalline, paraffin, oxidized lowdensity polyethylene or Fisher-Tropsch wax. These waxes may be usedindividually or in combination.

In certain embodiments, the metal to be coated may be in coil form orsheet form. The metal may be treated, immediately prior to coating,using a flame to remove residual surface contaminants, in certainembodiments. The metal may also be treated to modify its surface energyby using plasma treatment, ozone treatment, or corona treatment, priorto coating.

In certain embodiments, the metal may be aluminum, such as an 8011alloy, or the like.

In certain embodiments, the coating may be applied to the coil or sheetmetal using a direct roll coater, a reverse roll coater, a rod coater, apressure rod coater, a spray coater, a slot die coater, or a curtaincoater.

According to one embodiment, the coating may be applied at about 0.25milligrams per square inch to about 15 milligrams per square inch. Asused in this disclosure, “about” or “approximately” means within 10% ofthe given amount. Furthermore, the color coating may be applied directlyto the metal surface or to a clear (size coating) or lightly pigmented(base coating) tie-layer on the metal surface. In one embodiment, thecolor layer may be protected by an over-varnish coating.

In certain embodiments, the coating dryer may be a hot-air forcedconvection oven using a wicket conveyance system for metal sheets or ahot-air forced convection oven where the sheets remain flat.

In certain embodiments, an infrared heating system with forced airconvection, or an induction heating system with forced air convectionwhere the metal sheets are conveyed using a wicket conveyance system orwhere the sheets remain flat. Any other drying system may be used as isknown in the art.

During the coating drying process, metal (e.g., aluminum) coil or sheetmay be heated from ambient temperature, approximately 75 F, to atemperature between about 100° F. and about 500° F. in the oven. In apreferred embodiment, an aluminum coil or sheet is heated from ambienttemperature to a temperature between about 150° F. and about 250° F. inthe oven. The aluminum coil or sheet may be heated from ambienttemperature to the desired final temperature in approximately 5 to 120seconds. In the preferred embodiment, the aluminum coil or sheet isheated from ambient temperature to the desired temperature in 20 to 80seconds

In certain embodiments, the aluminum coil or sheet coated with awaterborne polymer may be overprinted using a free-radical UV ink or acationic UV ink.

Example 1: Primary EAA Coating Manufacture

An EAA dispersion was prepared using a 2 liter Parr Series 4520 benchtop stirred reactor equipped with quartz windows for viewing.

425 grams of Primacor 59801 EAA (The Dow Chemical Company, 2030 DowCenter, Midland, Mich. 48674), 1220.4 grams deionized water, 54.6 gramsof Aqua Ammonia 28% item 511561-1 (Hi Valley Chemical, 1134 W 850 N,Centerville, Utah 84014) (actual assay found to be 25.7% by measuringspecific gravity at 60 F and converting to weight percent ammonia) wasadded to the reactor vessel to produce 1700 grams of dispersion. Thereactor bomb was assembled and the vent closed, placed in the heatingmantle and heated, with mixing at 450 to 500 rpm until the reactantsreached 60-80 C, at which time the mixing speed was increased to 675rpm. The temperature continued to ramp to 110 C with constant agitationand the reactor vent closed. The batch was held at 110 C temperature forone hour resulting in all of the EAA being dispersed.

After the EAA was completely dispersed, the heating mantle was removedand agitation reduced to 300-450 rpm. Cooling was then initiated bydirecting 20-26 C water through the internal cooling coil until the EAAdispersion temperature was reduced to 28-35 C. The reactor was thenvented and the dispersion poured into a stainless steel beaker andallowed to de-aerate as it cooled to room temperature. Afterapproximately 24 hours, the EAA dispersion was passed through a 0.8 mmstainless steel strainer into a polyethylene storage container. Thedispersion was translucent in appearance.

Example 2: Primary EAA Sodium Ionomer Coating Manufacture

An EAA sodium ionomer dispersion was prepared using a 2 liter ParrSeries 4520 bench top stirred reactor equipped with quartz windows forviewing.

435.4 grams of Primacor 59801 EAA (The Dow Chemical Company, 2030 DowCenter, Midland, Mich. 48674), 1201.5 grams deionized water, 24.5 gramsof Aqua Ammonia 28% item 511561-1 (Hi Valley Chemical, 1134 W 850 N,Centerville, Utah 84014) (actual assay found to be 25.7% by measuringspecific gravity at 60 F and converting to weight percent ammonia) and38.6 grams Sodium Hydroxide, 50% Solution, product code 110014 (BrenntagSpecialties Inc., 1 Camino Sobrante #215, Orinda, Calif. 94563) wasadded to the reactor vessel to produce 1700 grams of dispersion. Thereactor bomb was assembled and the vent closed, placed in the heatingmantle and heated, with mixing at 450 to 500 rpm until the reactantsreached 60-80 C, at which time the mixing speed was increased to 675rpm. The temperature continued to ramp to 110 C with constant agitationand the reactor vent closed. The batch was held at 110 C temperature forone hour resulting in all of the EAA being dispersed.

After the EAA was completely dispersed, the heating mantle was removedand agitation reduced to 300-450 rpm. Cooling was then initiated bydirecting 20-26 C water through the internal cooling coil until the EAAdispersion temperature was reduced to 28-35 C. The reactor was thenvented and the dispersion poured into a stainless steel beaker andallowed to de-aerate as it cooled to room temperature. Afterapproximately 24 hours, EAA dispersion was passed through a 0.8 mmstainless steel strainer into a polyethylene storage container. Thedispersion was translucent in appearance.

Example 3: Michelman 4983R—White Base Coating Manufacture

Weighed 95 grams of the Michem® Prime 4983R (Michelman, Inc., 9080 ShellRoad, Cincinnati, Ohio) dispersion, into a Uline (part number S-19520) ½pint tin-plated steel can. Using a pipette, weighed 5 grams of SunChemical (WHD-9507) “Sunsperse White 6” (Sun Chemical Corporation, 35Waterview Boulevard, Parsippany, N.J. 07054) into the dispersion.Immediately, mixed the coating and pigment dispersion together using aCole-Parmer mixer (Model #50006-01) fitted with a 30 mm diameter 316 SSaxial impeller set at 700 rpm. The mixing speed was gradually increasedfrom 700 to 2000 rpm. Once at 2000 rpm, continued to mix for another 60seconds. The can was then closed for storage using a tin-plated steellid.

Example 4: Primary EAA—White Base Coating Manufacture

Weighed 95 grams of the EAA dispersion, created in Example 1, into aUline (part number S-19520) ½ pint tin-plated steel can. Using apipette, weighed 5 grams of Sun Chemical (WHD-9507) “Sunsperse White 6”(Sun Chemical Corporation, 35 Waterview Boulevard, Parsippany, N.J.07054) into the dispersion. Immediately, mixed the coating and pigmentdispersion together using a Cole-Parmer mixer (Model #50006-01) fittedwith a 30 mm diameter 316 SS axial impeller set at 700 rpm. The mixingspeed was gradually increased from 700 to 2000 rpm. Once at 2000 rpm,continued to mix for another 60 seconds. The can was then closed forstorage using a tin-plated steel lid.

Example 5: Primary EAA Sodium Ionomer—White Base Coating Manufacture

Weighed 95 grams of the EAA dispersion, created in Example 2, into aUline (part number S-19520) ½ pint tin-plated steel can. Using apipette, weighed 5 grams of Sun Chemical (WHD-9507) “Sunsperse White 6”(Sun Chemical Corporation, 35 Waterview Boulevard, Parsippany, N.J.07054) into the dispersion. Immediately, mixed the coating and pigmentdispersion together using a Cole-Parmer mixer (Model #50006-01) fittedwith a 30 mm diameter 316 SS axial blade impeller set at 700 rpm. Themixing speed was gradually increased from 700 to 2000 rpm. Once at 2000rpm, continued to mix for another 60 seconds. The can was then closedfor storage using a tin-plated steel lid.

Example 6: Michelman 4983R—Color Coating Manufacture

Weighed 87 grams of the Michem® Prime 4983R EAA dispersion into a Uline(part number S-19520) ½ pint tin-plated steel can. Using a pipette,weighed 13 grams of Sun Chemical (BPD-0015) “Sunsperse Blue 15:3” (SunChemical Corporation, 35 Waterview Boulevard, Parsippany, N.J. 07054)into the dispersion. Immediately, mixed the coating and pigmentdispersion together using a Cole-Parmer mixer (Model #50006-01) fittedwith a 30 mm diameter 316 SS axial impeller set at 700 rpm. The mixingspeed was gradually increased from 700 to 2000 rpm. Once at 2000 rpm,continued to mix for another 60 seconds. The can was then closed forstorage using a tin-plated steel lid.

Example 7: Primary EAA—Color Coating Manufacture

Weighed 87 grams of the EAA dispersion, created in Example 1, into aUline (part number S-19520) ½ pint tin-plated steel can. Using apipette, weighed 13 grams of Sun Chemical (BPD-0015) “Sunsperse Blue15:3” (Sun Chemical Corporation, 35 Waterview Boulevard, Parsippany,N.J. 07054) into the dispersion. Immediately, mixed the coating andpigment dispersion together using a Cole-Parmer mixer (Model #50006-01)fitted with a 30 mm diameter 316 SS axial impeller set at 700 rpm. Themixing speed was gradually increased from 700 to 2000 rpm. Once at 2000rpm, continued to mix for another 60 seconds. The can was then closedfor storage using a tin-plated steel lid.

Example 8: Primary EAA Sodium Ionomer—Color Coating Manufacture

Weighed 87 grams of the EAA dispersion, created in Example 2, into aUline (part number S-19520) ½ pint tin-plated steel can. Using apipette, weighed 13 grams of “Sunsperse Blue 15:3”, BPD-0015 (SunChemical Corporation, 35 Waterview Boulevard, Parsippany, N.J. 07054)into the dispersion. Immediately, mixed the coating and pigmentdispersion together using a Cole-Parmer mixer (Model #50006-01) fittedwith a 30 mm diameter 316 SS axial impeller set at 700 rpm. The mixingspeed was gradually increased from 700 to 2000 rpm. Once at 2000 rpm,continued to mix for another 60 seconds. The can was then closed forstorage using a tin-plated steel lid.

Example 9: Carnauba Wax Dispersion Manufacture

550 grams of “GC-704 CWE Carnauba Wax Emulsion” (Green Chem Coatings,Bishop, Ga.) was placed in 1200 mL Vollrath stainless steel beaker andagitated at 400 rpm at ambient temperature. 330 grams of deionized waterwere slowly added to result in a stable 25% solids carnauba waxemulsion. The dispersion was mixed for 60 seconds at ambient temperatureand then passed through a 0.8 mm stainless steel strainer into apolyethylene container for storage.

Example 10: Primary EAA—Over-Varnish Coating Manufacture

Weighed 90 grams of the EAA dispersion, created in Example 1, into aUline (part number S-19520) ½ pint tin-plated steel can. Using apipette, weighed 10 grams of “Carnauba Wax Dispersion” created inExample 9 into the dispersion. Immediately, mixed the coating and waxdispersion together using a Cole-Parmer mixer (Model #50006-01) fittedwith a 30 mm diameter 316 SS axial impeller set at 700 rpm. The mixingspeed was gradually increased from 700 to 2000 rpm. Once at 2000 rpm,continued to mix for another 60 seconds. The can was then closed forstorage using a tin-plated steel lid.

Example 11: Primary EAA Sodium Ionomer—Over-Varnish Coating Manufacture

Weighed 90 grams of the EAA dispersion, created in Example 2, into aUline (part number S-19520) ½ pint tin-plated steel can. Using apipette, weighed 10 grams of “Carnauba Wax Dispersion” created inExample 9 into the dispersion. Immediately, mixed the coating and waxdispersion together using a Cole-Parmer mixer (Model #50006-01) fittedwith a 30 mm diameter 316 SS axial impeller set at 700 rpm. The mixingspeed was gradually increased from 700 to 2000 rpm. Once at 2000 rpm,continued to mix for another 60 seconds. The can was then closed forstorage using a tin-plated steel lid.

Example 12: Lab Coating Aluminum Panels—Michelman 4983R Color Coating

Cut 4″ by 15″ lab sheets from 33.33″ by 35.72″ commercial sheets of0.009″ thick 8011 alloy aluminum. Flamed lab panels using a propanetorch to remove hydrophobic contaminants and to increase their surfaceenergy. Within 24 hours after flaming, carefully placed a lab sheet ontoa drawdown plate. Secured the lab sheet onto the drawdown plate using aspring loaded clip. Placed a clean Meyer #10 rod across the width of thelab sheet. Carefully pipetted approximately 5 mL of the “Example 6”color coating onto the lab sheet, directly in front of the Meyer rod.Using a smooth and uniform motion, drew the Meyer rod down the length ofthe lab sheet. Removed the coated lab sheet from the drawdown plate andplaced it into a holder prior to oven curing in lab oven (Sheldon Ovens#SMO5 89409-456). Placed coated lab sheets and holder into the oven withan air temperature of 210 F, for 60 seconds. Removed the dried labsheets from the oven and allowed them cool to ambient temperature.Stored coated lab sheets for further testing and deep draw performance.

Tested the flat lab sheets for “Coating Thickness”, “Sutherland Rub”,“Taber Coating Adhesion”, and “Blocking”.

The coating thickness was determined by measuring 6 locations on the4″×15″ panel using an ElektroPhysik MiniTest 720 (ElektroPhysik Dr.Steingroever GmbH & Co. KG, Pasteurstr. 15, 50735 Cologne, Germany).

The Sutherland rub was performed by cutting the coated panel into a 6″by 2.5″ rectangle, securing the rectangle onto the rubber base pad ofthe Sutherland rub tester, Model 2000 (Danilee Co., LLC, 27223 StarryMountain, San Antonio, Tex. 78260), attaching a piece of the 3M 261Xlapping film (Electronics Markets Materials Division 3M Electronics 3MCenter, Building 21-1W-10, 900 Bush Avenue St. Paul, Minn. 55144) to the41b weight, placing the 41b weight onto the 6″×2.5″ rectangle panel, andrubbing the sample for 500 cycles at a speed setting of 4. The sampleswere then ranked using the Sutherland Rub ranking scale shown in FIG. 6. In all of the results, the lower score is better than a higher score.

The Taber coating adhesion test was performed by cutting the coatedpanel into a 6″ by 1.5″ rectangle, cutting a cross-hatch pattern throughthe coating using a Gardco adhesion test multi-toothed cutter (Paul N.Gardner Company Inc., 316 N.E. First Street, Pompano Beach, Fla. 33060),placing a fresh strip of PA-280630 tape (manufactured by Interpolymerand sold by Paul N. Gardner Company Inc.) over the grid and smoothingthe tape over the cross-hatch with a finger, allowing the tape to fullyadhere to the sample for 60 to 120 seconds after smoothing, and rapidlypulling the tape off of the sample - using a force parallel and close tothe panel's surface. The samples were then ranked using the TaberAdhesion scale shown in FIG. 7 . For the results, the lower score isbetter than a higher score.

The blocking test was performed by cutting the coated panel into 5-4″ by2.5″ rectangles, stacking the rectangles on top of each other, placingthe stack in an oven pre-heated to 129 F, placing 11 pounds of weight ontop of the stack, leaving the samples in the oven for 4.5 hours, pullingthe samples from the oven, and ranking the samples for blocking, within5 minutes of removing from oven, using the following scale (all resultsare lower-the-better—LTB):

Blocking - Ranking Scale Rank Description 1 No Blocking 2 Slightblocking - commercially useable 3 Significant blocking throughoutstack - likely not commercially useable 4 Severe blocking for allsheets - commercially unusable 5 Solid black - commercially unusable

Results are shown in Table A.

TABLE A Flat Lab sheet Test Responses Taber Scratch Capmetal SheetCoating Sutherland Rub Test Cross Hatch Blocking Ranking Thickness (500Cycles) Ranking Test Ranking Scale (1-5, LTB) (μm) Scale (1-4, LTB)Scale (1-6, LTB) n = 4 6.20 4.0 6.0 3.35 ± 0.10 6.25 4.0 6.0 6.00 4.03.0 6.45 4.0 1.0 6.00 4.0 1.0 6.65 4.0 1.0

Created a 30 mm diameter by 60 mm long shell from the flat sheet using alab 3-draw press.

Applied a small amount of mineral oil onto a clean lint-free cloth andrubbed both sides of the coated sheet to apply a light layer oflubricating mineral oil. Placed the lubricated sheet into the 1st drawstation and created a 1st draw shell measuring ˜52 mm in diameter by ˜29mm in height.

If the first draw shell was acceptable, moved it to the second drawstation and placed the shell onto the draw tool. Created the second drawshell measuring ˜39 mm in diameter and ˜45 mm in height.

If second draw shell was acceptable, moved it to the third draw stationand placed the shell onto the draw tool. Created the third draw shellmeasuring ˜30 mm in diameter and ˜60 mm in height.

For shells with coating that survived the drawing from flat sheet to the30×60 form, a “Top Rub” and “Solvent Rub” test was performed todetermine the coating's durability.

The shell Top Rub testing was performed by placing an abrasive cardboardpiece onto the rubber base pad of the Digital Ink Rub Tester, Model10-18 (Testing Machines, Inc., 40 McCullough Drive, New Castle, Del.19720), securing the shell holder fixture in the tester, placing theshell with the top-side contacting the cardboard into the fixture, andrunning the rub tester for 500 cycles with no pause. Rubbed shells wereranked using the scale shown in FIG. 8 . For this ranking, lower scoresare better than higher scores.

The shell Solvent Rub testing was performed by placing a shell onto aglass bottle having a 1680 Glass Packaging Institute finish, and handrubbing, using very firm pressure, the shell with a ˜2″ by ˜3″ rectanglepaper towel soaked with 70% isopropyl alcohol (IPA) back and forth for30 cycles. The rubbed shells were ranked using the scale shown in FIG. 9. For this ranking, lower scores are better than higher scores.

Results are shown in Table B.

TABLE B Shelf Test Responses Top of Shell Rub Test 70% Isopropyl Alcohol(500 Cycles) Ranking Rub Test (30 Cycles) Scale (1-6, LTB) Ranking Scale(1-7, LTB) 6.0 5.0 5.0 5.0 6.0 6.0 6.0 4.0 3.5 4.8

Example 13: Lab Coating Aluminum Panels—Primary EAA Color Coating

Cut 4″ by 15″ lab sheets from 33.33″ by 35.72″ commercial sheets of0.009″ thick 8011 alloy aluminum. Flamed lab panels using a propanetorch to remove hydrophobic contaminants and to increase their surfaceenergy. Within 24 hours after flaming, carefully placed a lab sheet ontoa drawdown plate. Secured the lab sheet onto the drawdown plate using aspring loaded clip. Placed a clean Meyer #10 rod across the width of thelab sheet. Carefully pipetted approximately 5 mL of the “Example 7”color coating onto the lab sheet, directly in front of the Meyer rod.Using a smooth and uniform motion, drew the Meyer rod down the length ofthe lab sheet. Removed the coated lab sheet from the drawdown plate andplaced it into a holder prior to oven curing in lab oven (Sheldon Ovens#SMO5 89409-456). Placed coated lab sheets and holder into the oven withan air temperature of 210 F, for 60 seconds. Removed the dried labsheets from the oven and allowed them to cool to ambient temperature.Stored coated lab sheets for further testing and deep draw performance.

Tested the flat lab sheets for Taber Coating Adhesion, Sutherland Rub,Coating Thickness, and Blocking using the methods described in Example12. Results are shown in Table C.

TABLE C Flat Lab Sheet Test Responses Taber Scratch Capmetal SheetSutherland Rub Test Cross Hatch Blocking Ranking Coating (500 Cycles)Ranking Test Ranking Scale (1-5, LTB) Thickness Scale (1-4 LTB) Scale(1-6, LTB) n = 4 5.95 4.0 6.0 2.80 ± 0.59 6.50 4.0 5.0 6.35 4.0 6.0 6.204.0 6.0 6.55 4.0 2.0 5.75 4.0 1.0

Created a 30 mm diameter by 60 mm long shell from the sheet using a lab3-draw press. (See Example 12 for method).

For shells with coating that survived the drawing from flat sheet to the30×60 form, a “Top Rub” and “Solvent Rub” test was performed, using themethods described in Example 12, to determine the coating's durability.Results are shown in Table D.

TABLE D Shell Test Responses Top of Shell Rub Test 70% Isopropyl Alcohol(500 Cycles) Ranking Rub Test (30 Cycles) Scale (1-6, LTB) Ranking Scale(1-7, LTB) 6.0 4.8 5.0 3.5 3.0 4.0 3.5 4.0 4.0 3.5

Example 14: Lab Coating Aluminum Panels—Primary EAA Size and ColorCoating

Cut 4″ by 15″ lab sheets from 33.33″ by 35.72″ commercial sheets of0.009″ thick 8011 alloy aluminum. Flamed lab panels using a propanetorch to remove hydrophobic contaminants and to increase their surfaceenergy. Within 24 hours after flaming, carefully placed a lab sheet ontoa drawdown plate. Secured the lab sheet onto the drawdown plate using aspring loaded clip. Placed a clean Meyer #5 rod across the width of thelab sheet. Carefully pipetted approximately 5 mL of the “Example 1” sizecoating onto the lab sheet, directly in front of the Meyer rod. Using asmooth and uniform motion, drew the Meyer rod down the length of the labsheet. Placed the wet coated lab sheets and holder into the ovenpreheated to 250 F (121 C), for 60 seconds. Removed the dried lab sheetsfrom the oven and allowed them to cool to ambient temperature.

Secured the cured size-coated lab sheet onto the drawdown plate using aspring loaded clip. Placed a clean Meyer #10 rod across the width of thelab sheet. Carefully pipetted approximately 5 mL of the “Example 7”color coating onto the lab sheet, directly in front of the Meyer rod.Using a smooth and uniform motion drew the Meyer rod down the length ofthe lab sheet. Removed the coated lab sheet from the drawdown plate andplaced it into a holder prior to oven curing in lab oven (Sheldon Ovens#SMO5 89409-456). Placed coated lab sheets and holder into the oven withan air temperature of 210 F, for 60 seconds. Removed the dried labsheets from the oven and allowed them to cool to ambient temperature.Stored coated lab sheets for further testing and deep draw performance.

Tested the flat lab sheets for Taber Coating Adhesion, Sutherland Rub,Coating Thickness, and Blocking using the methods described in Example12. Results are shown in Table E.

TABLE E Flat Lab Sheet Test Responses Taber Scratch Capmetal SheetCoating Sutherland Rub Test Cross Hatch Blocking Ranking Thickness (500Cycles) Ranking Test Ranking Scale (1-5, LTB) (μm) Scale (1-4, LTB)Scale (1-6, LTB) n = 4 8.05 4.0 1.0 2.85 ± 0.25 7.80 4.0 1.0 7.70 4.01.0 8.25 4.0 1.0 7.90 4.0 1.0 7.95 4.0 1.0

Created a 30 mm diameter by 60 mm long shell from the sheet using a lab3-draw press. (See Example 12 for method).

For shells with coating that survived the drawing from flat sheet to the30x60 form, a “Top Rub” and “Solvent Rub” test was performed, using themethods described in Example 12, to determine the coating's durability.Results are shown in Table F.

TABLE F Shell Test Responses Top of Shell Rub Test 70% Isopropyl Alcohol(500 Cycles) Ranking Rub Test (30 Cycles) Scale (1-6, LTB) Ranking Scale(1-7, LTB) 4.0 3.5 4.0 3.3 2.0 3.5 2.3 3.8 2.8 3.3

Example 15: Lab Coating Aluminum Panels—Primary EAA Size, Color andOver-Varnish Coating

Cut 4″ by 15″ lab sheets from 33.33″ by 35.72″ commercial sheets of0.009″ thick 8011 alloy aluminum. Flamed lab panels using a propanetorch to remove hydrophobic contaminants and to increase their surfaceenergy. Within 24 hours after flaming, carefully placed a lab sheet ontoa drawdown plate. Secured the lab sheet onto the drawdown plate using aspring loaded clip. Placed a clean Meyer #5 rod across the width of thelab sheet. Carefully pipetted approximately 5 mL of the “Example 1” sizecoating onto the lab sheet, directly in front of the Meyer rod. Using asmooth and uniform motion, drew the Meyer rod down the length of the labsheet. Placed coated lab sheets and holder into the oven with an airtemperature of 210 F, for 60 seconds. Removed the dried lab sheets fromthe oven and allowed them to cool to ambient temperature.

Secured the cured size coated lab sheet onto the drawdown plate using aspring loaded clip. Placed a clean Meyer #10 rod across the width of thelab sheet. Carefully pipetted approximately 5 mL of the “Example 7”color coating onto the lab sheet, directly in front of the Meyer rod.Using a smooth and uniform motion, drew the Meyer rod down the length ofthe lab sheet. Removed the coated lab sheet from the drawdown plate andplaced it into a holder prior to oven curing in lab oven (Sheldon Ovens#SMO5 89409-456). Placed coated lab sheets and holder into the oven withan air temperature of 210 F, for 60 seconds. Removed the dried labsheets from the oven and allowed them to cool to ambient temperature.

Secured the cured size and color coated lab sheet onto the drawdownplate using a spring loaded clip. Placed a clean Meyer #10 rod acrossthe width of the lab sheet. Carefully pipetted approximately 5 mL of the“Example 10” over-varnish coating onto the lab sheet, directly in frontof the Meyer rod. Using a smooth and uniform motion, drew the Meyer roddown the length of the lab sheet. Removed the coated lab sheet from thedrawdown plate and placed it into a holder prior to oven curing in laboven (Sheldon Ovens #SMO5 89409-456). Placed coated lab sheets andholder into the oven with an air temperature of 210 F, for 60 seconds.Removed the dried lab sheets from the oven and allowed them to cool toambient temperature. Stored coated lab sheets for further testing anddeep draw performance.

Tested the flat lab sheets for Taber Coating Adhesion, Sutherland Rub,Coating Thickness, and Blocking using the methods described in Example12. Results are shown in Table G.

TABLE G Flat Lab Sheet Test Responses Taber Scratch Capmetal SheetCoating Sutherland Rub Test Cross Hatch Blocking Ranking Thickness (500Cycles) Ranking Test Ranking Scale (1-5, LTB) (μm) Scale (1-4, LTB)Scale (1-6, LTB) n = 4 13.20 2.8 1.0 2.90 ± 0.26 12.55 2.8 1.0 12.05 3.01.0 12.45 2.0 1.0 12.15 3.0 1.0 11.90 4.0 1.0

Created a 30 mm diameter by 60 mm long shell from the sheet using a lab3-draw press. (See Example 12 for method)

For coating that survived the drawing from flat sheet to a 30×60 shell,a “Top Rub” and “Solvent Rub” test was performed, using the methodsdescribed in Example 12, to determine the coating's durability. Resultsare shown in Table H

TABLE H Shell Test Responses Top of Shell Rub Test Alcohol (70%) (500Cycles) Ranking Rub Test (30 Cycles) Scale (1-6, LTB) Ranking Scale(1-7, LTB) 1.5 2.8 1.3 3.0 1.3 2.0 1.5 3.0 1.5 4.0

Example 16: Lab Coating Aluminum Panels—Primary EAA Sodium Ionomer Size,Color and Over-Varnish Coating

Cut 4″ by 15″ lab sheets from 33.33″ by 35.72″ commercial sheets of0.009″ thick 8011 alloy aluminum. Flamed lab panels using a propanetorch to remove hydrophobic contaminants and to increase their surfaceenergy. Within 24 hours after flaming, carefully placed a lab sheet ontoa drawdown plate. Secured the lab sheet onto the drawdown plate using aspring loaded clip. Placed a clean Meyer #5 rod across the width of thelab sheet. Carefully pipetted approximately 5 mL of the “Example 2” sizecoating onto the lab sheet, directly in front of the Meyer rod. Using asmooth and uniform motion, drew the Meyer rod down the length of the labsheet. Placed coated lab sheets and holder into the oven with an airtemperature of 210 F, for 60 seconds. Removed the dried lab sheets fromthe oven and allowed them to cool to ambient temperature.

Secured the cured size coated lab sheet onto the drawdown plate using aspring loaded clip. Placed a clean Meyer #10 rod across the width of thelab sheet. Carefully pipetted approximately 5 mL of the “Example 8”color coating onto the lab sheet, directly in front of the Meyer rod.Using a smooth and uniform motion, drew the Meyer rod down the length ofthe lab sheet. Removed the coated lab sheet from the drawdown plate andplaced it into a holder prior to oven curing in lab oven (Sheldon Ovens# SMO5 89409-456). Placed coated lab sheets and holder into the ovenwith an air temperature of 210 F, for 60 seconds. Removed the dried labsheets from the oven and allowed them to cool to ambient temperature.

Secured the cured size and color coated lab sheet onto the drawdownplate using a spring loaded clip. Placed a clean Meyer #10 rod acrossthe width of the lab sheet. Carefully pipetted approximately 5 mL of the“Example 11” over-varnish coating onto the lab sheet, directly in frontof the Meyer rod. Using a smooth and uniform motion, drew the Meyer roddown the length of the lab sheet. Removed the coated lab sheet from thedrawdown plate and placed it into a holder prior to oven curing in laboven (Sheldon Ovens #SMO5 89409-456). Placed coated lab sheets andholder into the oven with an air temperature of 210 F, for 60 seconds.Removed the dried lab sheets from the oven and allowed them to cool toambient temperature. Stored coated lab sheets for further testing anddeep draw performance.

Tested the flat lab sheets for Taber Coating Adhesion, Sutherland Rub,Coating Thickness, and Blocking using the methods described in Example12. Results are shown in Table I.

TABLE I Flat Lab Sheet Test Responses Taber Scratch Capmetal SheetCoating Sutherland Rub Test Cross Hatch Blocking Ranking Thickness (500Cycles) Ranking Test Ranking Scale (1-5, LTB) (μm) Scale (1-4, LTB)Scale (1-6, LTB) n = 4 14.05 1.5 1.0 1.75 ± 0.25 13.30 1.5 1.0 13.75 1.51.0 14.00 1.5 1.0 12.95 1.5 1.0 13.45 1.5 1.0

Created a 30 mm diameter by 60 mm long shell from the sheet using a lab3-draw press. (See Example 12 for method)

For coating that survived the drawing from flat sheet to a 30×60 shell,a “Top Rub” and “Solvent Rub” test was performed, using the methodsdescribed in Example 12, to determine the coating's durability. Resultsshown in Table J.

TABLE J Shell Test Responses Top of Shell Rub Test 70% Isopropyl Alcohol(500 Cycles) Ranking Rub Test (30 Cycles) Scale (1-6, LTB) Ranking Scale(1-7, LTB) 1.5 1.3 1.3 1.3 1.2 1.3 1.5 1.2 1.5 1.3

Example 17: Curing Process Results—Time and Temperature

An array (see Table K) was designed to determine the acceptable time andtemperatures required to cure a base coating (see Example 5), a colorcoating (see Example 8) over the base, and an over-varnish coating (seeExample 11) over the color. The coatings were applied to the panelsusing the same methods listed in Example 16 with the only exceptionbeing that the size coating was replaced by the base coating.

TABLE K Panel Panel Temperature Temperature Oven 0-time Oven Time OvenFinal Trial (° F.) (seconds) (° F.) 1 77 15 82 2 77 120 172 3 77 68 1504 77 15 121 5 77 120 251 6 77 15 88 7 77 120 112 8 77 120 112 9 77 120251 10 77 68 103 11 77 15 82 12 77 15 121 13 77 68 219 14 77 68 150 1577 60 129 16 77 95 148 17 77 30 108 18 77 60 143 19 77 30 125 20 77 60173 21 77 15 84 22 77 26 95 23 77 30 98 24 77 22 87 25 77 15 82 26 77 3089

Lab panels were coated with the base and cured using the panel startingtemperatures, residence times, and panel final temperatures listed inthe array. The base-coated samples were allowed to cool, over-coatedwith the color coating, and cured using the same curing temperatures andtimes listed in Table K. The color coated samples were then allowed tocool, over-coated with the over-varnish and cured using the same curingtemperatures and times listed in Table K. The flat panels were thentested for Coating Thickness, Sutherland Rub, Taber Coating Adhesion,and Blocking performance using the methods described in Example 12.Results shown in Table L.

TABLE L Flat Lab Sheet Test Responses Taber Scratch Coating SutherlandRub Test Cross Hatch Capmetal Sheet Thickness (500 Cycles) Ranking TestRanking Blocking Ranking Trial (μm) Scale (1-4, LTB) Scale (1-6, LTB)Scale (1-5, LTB) 1 13.17 3.0 1.0 3.9 2 12.74 2.0 1.0 1.7 3 12.83 2.0 1.01.0 4 13.09 1.5 1.0 1.0 5 12.55 1.5 1.0 1.0 6 12.65 1.5 1.0 4.0 7 12.353.0 1.0 3.3 8 12.85 3.0 1.0 2.3 9 12.04 1.5 1.0 1.0 10 12.84 3.5 1.0 4.211 12.87 3.5 1.0 4.5 12 12.88 2.0 1.0 1.5 13 12.61 1.5 1.0 1.5 14 12.701.5 1.0 1.0 15 12.71 1.5 1.0 2.0 16 12.59 1.5 1.0 1.9 17 11.92 1.5 1.01.7 18 11.53 1.5 1.0 1.4 19 12.61 1.5 1.0 1.2 20 12.14 1.5 1.0 1.0 2113.99 2.5 1.0 2.5 22 13.95 2.5 1.0 2.0 23 13.73 2.3 1.0 2.8 24 13.54 3.01.0 2.9 25 Coating failed to cure properly 26 13.63 4.0 1.0 2.4

All coated panels having minimally acceptable cured coatingcharacteristics were drawn into 30 mm diameter by 60 mm tall shellsusing the 3-draw lab press (method described in Example 12). The shellswith coating that survived the drawing process were then tested for “TopRub” and “Solvent Rub” performance using the methods described inExample 12. The results of these tests are shown in Table M

TABLE M Shell Test Responses Top of Shell Rub Test 70% Isopropyl Alcohol(500 Cycles) Ranking Rub Test (30 Cycles) Trial Scale (1-6, LTB) RankingScale (1-7, LTB) 1 1.5 1.5 2 1.5 1.5 3 1.3 1.3 4 1.8 7.0 5 1.5 1.3 6 1.52.0 7 1.8 7.0 8 1.5 7.0 9 1.3 1.5 10 1.8 7.0 11 1.8 7.0 12 1.5 1.5 131.5 1.5 14 1.5 1.8 15 1.5 1.5 16 1.5 1.5 17 1.5 1.5 18 1.5 1.8 19 1.31.0 20 1.3 1.8 21 1.5 6.0 22 1.5 5.5 23 1.8 4.3 24 1.8 7.0 25 No sampleto draw 26 1.5 7.0

Example 18: Coating Chemistry Process Results

Table N demonstrates how dispersion particle size, ionomer cation type,ionomerization percent, acrylic acid to ethylene ratio, and wax amountwould change the final coating performance.

TABLE N Amount 3460 EAA 5380I EAA Ionomer Level 17% TS DispersionCarnauba Wax (% Particle Size Ionomer (%5980I AA Added to 5380I solidson EAA Trial (nm) Cation Neutralized) Dispersion (%) Total Solids) 1 7.1K 38.0 15.0 6.0 2 8.6 K 42.0 30.0 6.0 3 13.9 K 42.0 1.5 12.0 4 7.5 K42.0 4.5 0.0 5 15.4 Na 38.0 30.0 3.0 6 13.7 K 39.2 13.5 7.2 7 11.1 Na38.0 30.0 10.8 8 12.9 Na 38.0 16.5 12.0 9 16.0 K 38.0 0.0 0.0 10 10.9 Na41.0 13.5 6.0 11 8.7 K 40.8 0.0 4.8 12 7.9 K 38.8 30.0 0.0 13 13.9 K42.0 22.5 0.0 14 12.9 Na 38.0 16.5 0.0 15 15.4 Na 38.0 0.0 10.8 16 11.6K 38.0 30.0 12.0 17 8.5 K 38.4 0.0 12.0 18 10.9 Na 41.0 13.5 6.0 19 18.1Na 42.0 0.0 0.0 20 9.7 Na 42.0 0.0 12.0 21 7.3 K 41.2 25.5 12.0 22 18.1Na 42.0 30.0 12.0 23 11.1 Na 38.0 0.0 0.6 24 9.7 Na 42.0 30.0 0.0 Allcoatings contained 51% Sunsperse Blue 15:3 dispersion based on total EAAsolids.

Color coatings were made from each of the 24 trial coatings by mixingSunsperse Blue 15:3 pigment dispersion with the appropriate amount ofEAA dispersion to result in a pigment dispersion to EAA solids of 51%.As with previous examples, the samples were made in Uline (part numberS-19520) ½ pint tin-plated steel cans by mixing with a Cole-Parmer mixer(Model#50006-01), fitted with a 30mm diameter 316 SS axial impeller setat 700 rpm. The mixing speed was gradually increased from 700 to 2000rpm. Once at 2000 rpm, continued mixing for another 60 seconds. The canwas then closed for storage using a tin-plated steel lid.

Coated lab panels were created and heated in 210 F air, for 60 seconds.The flat panels were then tested for Taber Coating Adhesion, SutherlandRub, Coating Thickness, and Blocking performance using the methodsdescribed in Example 12. The results are shown in Table O.

TABLE O Flat Lab Sheet Test Responses Taber Scratch Coating SutherlandRub Test Cross Hatch Capmetal Sheet Thickness (500 Cycles) Ranking TestRanking Blocking Ranking Trial (μm) Scale (1-4, LTB) Scale (1-6, LTB)Scale (1-5, LTB) 1 6.24 1.8 1.0 2.0 2 6.44 1.5 1.0 2.1 3 7.41 3.0 1.01.0 4 6.28 3.3 1.0 4.5 5 6.53 2.0 1.0 1.0 6 6.95 2.3 1.0 1.4 7 6.33 1.51.0 2.0 8 6.27 2.0 1.0 1.0 9 7.38 4.0 1.0 3.2 10 6.45 1.3 1.0 1.8 117.37 1.5 1.0 2.1 12 6.22 1.3 1.0 4.2 13 6.58 3.8 1.0 2.0 14 6.23 3.8 1.02.0 15 6.79 2.5 1.0 1.0 16 6.08 1.2 1.0 1.0 17 6.62 1.3 1.0 1.6 18 6.581.3 1.0 2.1 19 7.10 3.5 1.0 2.0 20 6.61 1.3 1.0 2.8 21 6.40 1.3 1.0 1.022 6.58 2.0 1.0 1.0 23 6.75 2.0 1.0 2.4 24 5.78 3.8 1.0 3.3

The coated flat metal for each trial was then drawn into a 30 mmdiameter by 60 mm tall shells using the method described in Example 12.The shells with coating that survived the drawing process were thentested for “Top Rub” and “Solvent Rub” performance using the methodsdescribed in Example 12. The results of these tests are shown in TableP.

TABLE P Shell Test Responses Top of Shell Rub Test 70% Isopropyl Alcohol(500 Cycles) Ranking Rub Test (30 Cycles) Trial Scale (1-6, LTB) RankingScale (1-7, LTB) 1 1.5 5.5 2 2.0 5.9 3 1.5 7.0 4 1.5 5.0 5 1.5 4.8 6 1.55.0 7 1.5 4.3 8 1.7 4.8 9 1.5 4.3 10 1.5 5.0 11 1.8 4.3 12 1.5 5.0 131.5 6.0 14 1.5 5.0 15 1.5 6.0 16 1.5 5.0 17 1.5 5.2 18 1.5 5.0 19 1.57.0 20 1.5 5.3 21 1.5 4.5 22 1.5 4.8 23 1.5 3.8 24 1.5 5.0

Example 19: Commercial Roll Coating Aluminum Panels—Primary EAA SodiumIonomer Base/Color/Over Varnish and Interior Lacquer Coating

Five gallons of each coating (white base, color, over-varnish) wasproduced using Primary EAA Sodium Ionomer (same formulation used tocreate Example 2) prepared in a 60 gallon reactor. “White Base Coating”was prepared by adding 2.1 pounds of “Sunsperse White 6” to 37.9 poundsof Primary EAA Sodium Ionomer with agitation, mixed to homogeneouscomposition and then filtered through a 150 micron bag into a plastic 5gallon pail. The “Color Coating” was prepared by adding 5.4 pounds of“Sunsperse Blue 15:3” to 34.6 pounds of Primary EAA Sodium Ionomer withagitation, mixed to homogeneous composition and then filtered through a150 micron bag into a plastic 5 gallon pail. The “Over-varnish” wasprepared by adding 4.2 pounds of the Carnauba Wax Dispersion (sameformulation used to create Example 9) to 35.8 pounds of Primary EAASodium Ionomer with agitation, mixed to homogeneous composition and thenfiltered through a 150 micron bag into a plastic 5 gallon pail.

Set-up a commercial direct roll coater capable of handling, 0.009″thick, 35.7″×33.3″ flat 8011 aluminum sheets. Ran coater at 60 sheetsper minute using a 12″ diameter urethane coating application roller,rotating at 72 rpm. Immediately after the coating was applied to thesheet, it was dried and the EAA film formed in a Wagner Litho ovenhaving a time/temperature profile shown in FIG. 10 .

The first coating applied was the white base. This coating was curedthrough the wicket-conveyance oven and the base-coated sheets werereturned to their original orientation and sent back to the coater feedsystem. The liquid base coating was removed from the roll coater systemand the system was cleaned using water and primed with the colorcoating. The base coated sheets were then over-coated with the colorcoating and cured using the same oven curve. The cured sheets were againreturned to the coater feed, without flipping, and the system was purgedof the liquid color coat, cleaned using water, and primed with theover-varnish (used the over-varnish as an interior lacquer). The“interior lacquer” was applied to the bare metal and cured using thesame oven curve and returned to the coater feed, without flipping, forthe final over-varnish application. No purging or cleaning of the systemwas required between these coating applications since the interiorlacquer and the over-varnish coatings were the same. The over varnishedsamples were fed through the curing oven with the same oven curvecompleting the metal coating for screw-cap manufacture.

Approximately 500 fully coated sheets were stacked on a pallet andshipped by truck to a commercial screw-cap manufacturing facility forfurther processing. Upon arrival at the cap manufacturing company, ablocking test was set-up. This was done by placing temperature sensorson the 500 sheet pallet, setting a standard 900 pound pallet ofcommercial metal on top of the 500 sheets and storing the pallets in thereceiving yard. The pallets remained in the receiving yard for four (4)days with temperatures cycling between 70 and 110 F. After the fourthday, the 900 lb. pallet was removed and the 500 sheets were checked forblocking. No sheets blocked.

Prior to running the sheets on a commercial screw cap forming line, theflat coated metal was lab tested for Taber Coating Adhesion, SutherlandRub, Coating Thickness, and Blocking using the methods described inExample 12. Results are shown below in Table Q.

TABLE Q Flat Lab Sheet Test Responses Taber Scratch Capmetal SheetCoating Sutherland Rub Test Cross Hatch Blocking Ranking Thickness (500Cycles) Ranking Test Ranking Scale (1-5, LTB) (μm) Scale (1-4, LTB)Scale (1-6, LTB) n = 4 8.25 1.5 1.0 1.00 ± 0.00 7.85 1.5 1.0 9.75 1.51.0 10.30 1.5 1.0 9.35 1.8 1.0

After testing the flat sheets, created screw-caps by running themthrough a commercial manufacturing line. The caps were tested for “TopRub” and “Solvent Rub” performance using the methods described inExample 12. The results of these tests are in Table R.

TABLE R Shell Test Responses Top of Shell Rub Test 70% Isopropyl Alcohol(500 Cycles) Ranking Rub Test (30 Cycles) Scale (1-6, LTB) Ranking Scale(1-7, LTB) 1.5 2.0 1.5 2.3 1.5 2.3 1.5 1.5

The caps were applied to bottles having a standard GPI 1680 finish.

Cap application was done using an Andre Zalkin, Model TM3, single-headcapper (5 Route André Zalkin, 27390 Montreuil-l'Argillé, France). Thecapper was fitted with a Zalkin 30×60 Stelvin-type capper head andset-up using industry standard top load, thread rollers, thread rollerforce, pilfer rollers, pilfer roller force, and reform settings. Thecapped samples were allowed to sit for 24 hours and were then tested forslip and break torques using a Torqo II (Mesa Labs, 12100 West 6th Ave.Lakewood, Colo. 80228). The results are shown in Table S.

TABLE S Slip Break Torque Torque Trial ID (in-lbs) (in-lbs) 1 14.07 8.872 15.57 9.63 3 12.06 8.88 4 12.66 8.97 5 17.61 12.51 6 15.66 10.14 712.06 8.10 8 12.57 7.35 9 13.62 8.04 10 13.11 8.49 11 13.26 11.22 1214.10 7.08

After removing the caps, the interior lacquer was visually checked todetermine if the capping and cap removal process damaged the coating. Noflaking or removal of the coating was observed.

The various embodiments described above are provided by way ofillustration only and should not be construed to limit the claimedinvention. Those skilled in the art will readily recognize variousmodifications and changes that may be made to the claimed inventionwithout following the example embodiments and applications illustratedand described herein, and without departing from the true spirit andscope of the claimed invention, which is set forth in the followingclaims.

What is claimed:
 1. A method of forming a screw cap closure, the method comprising: coating a metal substrate with a first coating composition, the first coating composition comprising a dispersion of ethylene acrylic acid copolymer in water; and curing the first coating composition by applying heat to form a first coating on the metal substrate, wherein the metal substrate and the first coating are configured to be deep drawn to form a screw cap closure.
 2. The method of claim 1, wherein the first coating comprises at least one of a pigment or a wax.
 3. The method of claim 1, wherein the ethylene acrylic acid copolymer is present in the dispersion in an amount from 15 percent to 45 percent, by weight.
 4. The method of claim 1, wherein the ethylene acrylic acid copolymer comprises acrylic acid functional groups, and wherein 25 to 100 molar percent of the acrylic acid functional groups have been neutralized with at least one of ammonium hydroxide or sodium hydroxide.
 5. The method of claim 4, wherein the ammonium hydroxide neutralized about 30 molar percent of the acrylic acid functional groups and the sodium hydroxide neutralized about 40 molar percent of the acrylic acid functional groups.
 6. The method of claim 1, wherein the first coating composition contains no volatile organic compounds (VOCs) and comprises a 4,4′-(propane-2,2-diyl) diphenol (BPA) non-intent status.
 7. The method of claim 1, wherein curing the first coating composition comprises heating the metal substrate to a temperature from about 150° F. (65.6° C.) to about 250° F. (121° C.).
 8. The method of claim 1, further comprising: mixing the ethylene acrylic acid copolymer with water and a base to obtain a mixture; and heating the mixture under agitation to form the first coating composition.
 9. The method of claim 1, further comprising coating the metal substrate with a second coating composition, the second coating composition comprising ethylene acrylic acid copolymer and a pigment.
 10. The method of claim 9, further comprising coating the metal substrate with a third coating composition, the third coating composition comprising ethylene acrylic acid copolymer and a wax.
 11. The method of claim 1, further comprising deep drawing the coating and the metal substrate to form the screw cap closure.
 12. A method of forming a screw cap closure, the method comprising: obtaining a metal substrate coated with a coating comprising ethylene acrylic acid copolymer; and deep drawing the metal substrate and the coating to form a screw cap closure.
 13. The method of claim 12, wherein the coating was applied to the metal substrate as a dispersion of the ethylene acrylic acid copolymer in water, and wherein the coating was cured by applying heat.
 14. The method of claim 12, wherein the coating comprises at least one of a pigment or a wax.
 15. The method of claim 12, wherein the ethylene acrylic acid copolymer comprises acrylic acid functional groups, and wherein 25 to 100 molar percent of the acrylic acid functional groups have been neutralized with at least one of ammonium hydroxide or sodium hydroxide.
 16. The method of claim 15, wherein the ammonium hydroxide neutralized about 30 molar percent of the acrylic acid functional groups and the sodium hydroxide neutralized about 40 molar percent of the acrylic acid functional groups.
 17. The method of claim 12, wherein the coating contains no volatile organic compounds (VOCs) and comprises a BPA non-intent status.
 18. The method of claim 12, wherein the screw cap closure comprises a diameter of about 30 mm and a length of about 60 mm.
 19. The method of claim 12, wherein the screw-cap closure comprises multiple coating layers, with each coating layer comprising an ethylene acrylic acid copolymer.
 20. The method of claim 19, wherein the multiple coating layers comprise a lacquer layer disposed on an interior surface of the screw-cap closure and at least one coating layer on an exterior surface of the screw-cap closure. 